What are the first-line empirical antibiotics for Urinary Tract Infection (UTI) in a pregnant patient?

From the Guidelines

Nitrofurantoin is the first-line empirical antibiotic for Urinary Tract Infection (UTI) in a pregnant patient.

First-line Treatment Options

• Nitrofurantoin macrocrystals: 50–100 mg q.i.d. for 5 days 1
• Nitrofurantoin monohydrate or macrocrystals: 100 mg b.i.d. for 5 days 1
• Nitrofurantoin macrocrystals prolonged release: 100 mg b.i.d. for 5 days 1
• Fosfomycin trometamol: 3 g single dose, although its use in pregnancy is not as well-studied as nitrofurantoin 1

Rationale

The European Association of Urology guidelines recommend nitrofurantoin as a first-line treatment for uncomplicated cystitis in women, including pregnant women 1. The American College of Physicians also recommends nitrofurantoin for 5 days as a best practice advice for uncomplicated bacterial cystitis in women 1. However, it is essential to note that trimethoprim and trimethoprim-sulfamethoxazole are not recommended in the first trimester and last trimester of pregnancy, respectively 1.

Considerations

The optimal duration of therapy will be antimicrobial-specific, and nitrofurantoin and β-lactam antimicrobials are preferred due to their safety in pregnant women 1. A single dose of fosfomycin is effective for clearance of bacteria in the urine, but its use in pregnancy requires further study 1.

From the Research

First-Line Empirical Antibiotics for UTI in Pregnant Patients

• The first-line empirical antibiotics for urinary tract infections (UTIs) in pregnant patients include:
  • Nitrofurantoin 2, 3, 4, 5
  • Fosfomycin 2, 3, 4, 5
  • Trimethoprim-sulfamethoxazole (when resistance levels are <20%) 2, 4, 6
• These antibiotics have minimal collateral damage and resistance, and are considered appropriate treatments for UTIs in pregnant women 2, 3
• The choice of antibiotic should take into account the patient's symptoms, test results, and local resistance patterns 2, 3, 5

Considerations for Antibiotic Selection

• The selection of an antibiotic should consider factors such as pharmacokinetics, spectrum of activity, resistance prevalence, potential for adverse effects, and duration of therapy 4, 5
• Ideal antimicrobial agents for UTI management have primary excretion routes through the urinary tract to achieve high urinary drug levels 4
• Special considerations should be taken into account for pregnant women, including the potential risks and benefits of each antibiotic 2, 3, 4

Bacterial Resistance and Antibiotic Sensitivity

• Resistance to fluoroquinolones, beta-lactams, and trimethoprim-sulfamethoxazole is increasing, making it essential to consider local resistance patterns when selecting an antibiotic 2, 5
• Nitrofurantoin and fosfomycin have been shown to have high sensitivity against common uropathogens, including E. coli and Klebsiella spp. 3, 5